A large number of the ironware was excavated in Hokkaido. These are very important in considering the ironware excavated in Honshu. The ironware of Honshu was rare to excavate, because ironware were recycled in Honshu. Among the ironware in Hokkaido, there is unique sword called Ezo-gatana or Ainu’s sword which is not discovered in Honshu. This sword is seems to be the sword for ceremonial use. We search the difference of the manufacturing process with the Japanese sword excavated from the same site from the X - ray transmission image.